It's not just Warcraft, it's a Warcraft assassin. Assassins are the most common class in the game, and they keep putting them in even if we're still stuck with just 7 supports.
Diablo has no support hero and they're giving us Joanna. A warrior. Like almost every Diablo hero they put in, and they still have Leoric and the Butcher planned that still are warrior-themed heroes; they COULD make them specialists, maybe the butcher could even be an assassin but... really?
And Starcraft has no Warriors, just a lot of assassins. Really, I wonder what they're thinking up there.